MATTE BLACK FINISH: The rollator plastic knob features a durable matte black coating that resists wear over time and provides a textured grip for added control. ZINC-PLATED STEEL: Bolts and washers for walker accessories are constructed from zinc-plated steel, offering resistance to moisture and various weather conditions. NON-SLIP: Rollator accessories are designed to remain secure and prevent slipping, helping to ensure the walker remains stable and safe during use. EASY TO USE: Walker accessories require simple assembly and can be attached in just a few minutes. CONTENTS: The package includes 2 plastic knobs and 2 bolts with washers. These components can be easily assembled by hand without tools. When shopping, please review the product title and description carefully to confirm size, dimensions, and specifications to ensure compatibility with your needs. We want you to be completely satisfied with your purchase. If you have any questions or concerns, please . We are here to help and will do our best to assist you. Thank you for choosing our product. We hope you enjoy it!